202 The American Antelope, or Prong Buck. [ April, 
surface rests the epidermis, if we may use that term, where con- 
stant activity is ever present. As this epidermis or outer coating 
of the skin on the human subject, for instance, is constantly wear- 
ing away, so must it be constantly renewed by new growths. For 
this purpose minute cells are constantly being formed upon or next 
to the papilla. The new cells, being at the very bottom, neces- 
sarily force up their predecessors, which become more and more 
flattened out in the form of scales. Of these flattened scales the 
epidermis is formed ; as they approach the surface, they become 
dryer and harder and of a horny nature, ‘even on the most deli- 
cate skin, and in that condition these horny scales or flattened 
cells are worn off by friction. It is these flattened cells which 
constitute all horns, hoofs, nails, and claws; and so we are not 
disappointed when we find that the horns of our antelope are 
composed of these same flattened and dried-up cells. As these 
cells are forced up and flattened out, they cohere in a mass large 
enough to form the horn, and in obedience to some law of nature 
are molded into the proper form. When enough of these flat- 
tened and hardened cells have been accumulated and consolidated 
to constitute the horn at a given place, it cleaves off from the 
softer inner portion of the cuticle within, leaving a stratum of 
epidermis covering the corium. 
While the mode of growth of this horn so exactly corresponds 
with that of other and persistent horns, its progress is necessarily 
widely different. The growth of other horns is very slow and 
uniform, proceeding from the epidermis at their bases, while this 
horn, instead of taking a life-time to complete its growth, must 
be finished in a few months. It is not pushed up and enlarged a 
little each year by a slow accumulation of these flattened and 
hardened cells at its base, but it first shoots up with astonishing 
rapidity from the very top of the core, till the old horn is pushed 
off and the new one above is far advanced, while over all the 
rest of the core the cuticle has manifested no unusual activity, 
but simply a moderate state of vitality is exhibited. When 
growth of the horn above the end of the core is completed, the 
time has arrived for the formation of the new horn below. That 
part of the epidermis which had been so active and performed 
such extraordinary work in so short a time relapses into a state 
of quiet, and a section below has suddenly become aroused to * 
state of great activity, till it has done its work and completed its 
horny crust, when in a few days, or weeks at most, it in tum 
relapses into quiet ; and so, as the growth progresses downward, 
